Electron-phonon coupling and Peierls transition in metallic nanotubes

TL;DR

This paper investigates the electron-phonon interactions in (5,5) metallic nanotubes, revealing a specific phonon mode responsible for a Peierls transition with a transition temperature around 15 K.

Contribution

It identifies the specific phonon mode involved in the Peierls transition and provides a mean-field estimate of the transition temperature in metallic nanotubes.

Findings

The conduction electrons couple to a zone edge phonon with Kekule symmetry.

The estimated transition temperature is approximately 15 K.

The coupling mechanism differs from previous assumptions.

Abstract

We reexamine the putative Peierls transition in a (5,5) metallic nanotube. We show that the conduction electrons at the Fermi level do not couple to the longitudinal acoustic phonon but rather to a folded-in graphene zone edge phonon having the proper Kekule modulation symmetry. The calculation for the mean-field transition temperature gives 15 K, a value comparable to previous estimates. We discuss the significance of this transition temperature.